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Timing

The Timing page in TREDIS provides interfaces for setting the time periods in your project, as well as analysis segments.

Project Timing

Construction Years and Operations Years in your project can be set by clicking on the handle on the range of years and dragging left or right.

Timing Page
Timing Page

Construction Years are when capital and design costs are modeled, for both spending and impacts.

Operations Years are when recurring maintenance and operations costs and impacts are modeled.

Construction Years and Operations Years may overlap for as long as needed. For example, a road widening might open a portion of the road to use mid-construction, at which point travel and operational costs may be relevant while construction costs and impacts are still modeled as well.

The Constant Dollar Year is the date corresponding to the contract and defines the dollar year of all inputs and results. In a TREDIS contract with the year 2024, the underlying economic data set used for economic relationships will be based in 2024 data, and all inputs and results will be in 2024 dollars.

The Inventory Interest Rate is a percentage representing the interest rate of private capital, which will be used for calculations of freight cost logistics. It is not recommended to change this except under special circumstances and in consultation with TREDIS support, since the default is the basis of calibration for components of the logistics model.

Analysis Segments

TREDIS allows you to divide your travel into segments to see how distinct groups of travelers affect the benefits and impacts of the entire system. All segments are added together to make up the entire analysis, so any one segment may not be a subset of another. Common uses of segments include differentiating periods of the day – e.g. "AM Peak" and "PM Peak" segments – or demographic groups – e.g. "EJ population" and "Non-EJ population" segments.

Each mode and region will be repeated on the Travel page for each segment defined, and some reports likewise give data on each segment separately (as well as a total of all segments). For example, if weekday Passenger Car - Personal travel makes up only a portion of traffic on weekdays, but nearly all of travel on the weekends, a "Weekday" segment and a "Weekend" segment will allow you to both enter and track the periods separately.

Keep in mind that activity in one segment doesn't affect activity in the other, even when divided into sequential segments, such as time of the day, so that a period labeled "AM Peak" will have no effect on another labeled "PM Peak".